Use of hydrogen sulphide and N-ethylmaleimide in the post-irradiation modification of oxic and anoxic components of damage in Hordeum vulgare

The post-irradiation modification of radiosensitivity of barley seeds with about 7% water content by hydrogen sulphide and N-ethylmaleimide (NEM) applied during oxygenated or oxygen-free hydration was studied. H₂S, which causes about 18% seedling injury to unirradiated seeds, effectively decreases the post-irradiation oxygen-dependent damage (Powers' class III). NEM dramatically enhances the magnitude of an O₂-independent component of damage. It also affords a small degree of protection against the post-irradiation oxic damage. The mechanisms possibly involved are briefly discussed.